Motility in the Small Intestine The most common

Motility in the Small Intestine • The most common motion of the small intestine is _ – It is initiated by _ (Cajal cells) – Moves contents steadily toward the _

Motility in the Small Intestine • After nutrients have been absorbed: – Peristalsis begins with each wave starting distal to the previous – Meal remnants, bacteria, mucosal cells, and debris are _

Control of Motility • Local enteric neurons of the GI tract coordinate intestinal motility • _________________ cause: – Contraction and shortening of the _ – Shortening of _ – Distension of the intestine

Control of Motility • Other impulses relax the circular muscle • The – Relax the _ – Allow chyme to pass into the large intestine

Large Intestine • Has three unique features: – • three bands of longitudinal smooth muscle in its muscularis – • pocketlike sacs caused by the tone of the teniae coli – Epiploic appendages •

Large Intestine • Is subdivided into the – – – • The saclike cecum: – Lies below the ileocecal valve in the right iliac fossa – Contains a wormlike vermiform appendix

Colon • Has distinct regions: ascending colon, hepatic flexure, transverse colon, splenic flexure, descending colon, and sigmoid colon • The _____________ joins the _ • The _______________ opens to the exterior _

Sphincters of the Anus • The anus has ______ sphincters: – __________________ anal sphincter • composed of _________________________ muscle • These sphincters are closed _

Large Intestine: Microscopic Anatomy • Colon mucosa is _______________ epithelium except in the anal canal • Has numerous deep ________ lined with _

Large Intestine: Microscopic Anatomy • Anal canal mucosa is _ • Anal sinuses _ • Superficial venous plexuses are associated with the anal canal • Inflammation of these veins results in itchy varicosities called _

Bacterial Flora • The ____________ of the large intestine consist of: – Bacteria surviving the small intestine that enter the cecum and – Those entering via the anus • These bacteria: – – Release irritating acids and _ – Synthesize ______________ and vitamin K

Functions of the Large Intestine • Other than digestion of enteric bacteria, _ • Vitamins, water, and electrolytes _ • Its major function is _________________ toward the anus • Though essential for comfort, the colon is _

Motility of the Large Intestine • – Slow segmenting movements that move the contents of the colon – contract as they are _ • Presence of _ – Activates the _ – Initiates peristalsis that _

Defecation • ___________ of rectal walls caused by feces: – _______________ of the rectal walls – Relaxes the ________ anal sphincter • Voluntary signals stimulate relaxation of the external anal sphincter and defecation occurs

Chemical Digestion: Carbohydrates • Absorption: – Enter the _ – Transported to the ______via the ________________ • Enzymes used: – _______________________ amylase, –

Chemical Digestion: Proteins • Absorption: similar to carbohydrates • Enzymes in the stomach – • Enzymes in the _ – ________________ – trypsin, chymotrypsin, and carboxypeptidase – ________________ – aminopeptidases, carboxypeptidases, and dipeptidases

Chemical Digestion: Fats • Absorption: Diffusion into intestinal cells where they: – – Enter _____________ and are transported to systemic circulation _

Chemical Digestion: Fats • Glycerol and short chain fatty acids are: – Absorbed into the _ – Transported via the _ • Enzymes/chemicals used: – bile salts –

Chemical Digestion: Nucleic Acids • Absorption: ___________ via membrane carriers • Absorbed in villi • transported to liver via hepatic portal vein • Enzymes used: – pancreatic ribonucleases and deoxyribonuclease in the small intestines

Malabsorption of Nutrients • Results from anything that – interferes with _ – _______________ the intestinal mucosa (e. g. , bacterial infection)

Malabsorption of Nutrients • Gluten enteropathy _ – _____________ damages the intestinal villi – reduces the _ • Treated by eliminating gluten from the diet (all grains but rice and corn)

Cancer • Stomach and colon cancers _________________ or symptoms • Metastasized ___________ frequently cause _ • Prevention is by regular dental and medical examinations

Cancer • _______________ is the 2 nd largest cause of cancer deaths in males – (_____________ is 1 st) • Forms from benign mucosal tumors – – formation increases with age • Regular colon examination should be done for _

Kidney Functions • Filter 200 liters ________ daily, allowing toxins, metabolic wastes, and excess ions to leave the body in urine • _______________ and chemical makeup of the blood • Maintain the ___________ between water and salts, and acids and bases

Other Renal Functions • ______________ during prolonged fasting • Production of _________ to help ______________ and _______________ to stimulate ________ production • Activation of vitamin D

Other Urinary System Organs • – provides a temporary storage reservoir for urine • Paired ureters – transport urine from _ • Urethra – transports urine from the _

Figure 25. 1 a

Layers of Tissue Supporting the Kidney • – fibrous capsule that prevents kidney infection • Adipose capsule – ____________ that cushions the kidney and helps _________ to the body wall • Renal fascia – outer layer of ________________ that anchors the kidney

Internal Anatomy (Frontal Section) • – the light colored, _____________ superficial region • Medulla – exhibits cone-shaped _____________ separated by columns – The medullary pyramid and its surrounding capsule constitute a lobe • – flat funnel shaped tube lateral to the hilus within the renal sinus

Internal Anatomy • Major calyces – large _______________ of the renal pelvis – _______________ draining from papillae – Empty urine into the pelvis • Urine flows through the _